A power battery heating system, heating control method, device and equipment

Abstract

The present invention provides a power battery heating system, heating control method, device, and apparatus. The power battery heating system includes: a battery pack and a motor controller; the battery pack includes: a first battery module and a second battery module connected via a first switch; the positive electrode of the first battery module is connected to the upper bridge arm of the first target phase in the IGBT module via the second switch; the positive electrode of the second battery module is connected to the upper bridge arm of the second target phase and the upper bridge arm of the third target phase in the IGBT module via a third switch; the negative electrode of the first battery module and the negative electrode of the second battery module are connected to the lower bridge arm of the first target phase, the lower bridge arm of the second target phase, and the lower bridge arm of the third target phase via a fourth switch; and the upper bridge arm of the first target phase is connected to the upper bridge arm of the second target phase via a fifth switch. This solution not only provides power to the motor controller via the battery pack, but also uses the heat generated by charging and discharging the battery modules to heat the power battery, thereby improving the heating rate.

Description

Technical Field

[0001] The present invention relates to the field of electric vehicle control technology, and in particular to a power battery heating system, a heating control method, a device and equipment. Background Art

[0002] In the field of pure electric vehicles, lithium-ion batteries have become the absolute mainstream power battery for current vehicles due to their high energy density, wide discharge range, and long cycle life. However, the poor low-temperature performance of lithium-ion batteries (such as the inability to output high power at low temperatures and poor charge and discharge performance) has become a major obstacle to their promotion in cold regions. Before breakthroughs in battery technology are achieved, this characteristic of lithium-ion batteries is a common problem faced by all pure electric vehicle manufacturers. Currently, external heating methods are commonly used to address the problem of power battery performance degradation at low temperatures. This is achieved by adding a dedicated electric heating system to the power battery, such as an electric heater or a liquid heater, to heat the power battery from the outside to increase its temperature to meet performance requirements. However, this method does not achieve satisfactory results because the battery energy consumed to generate this additional heat is relatively high compared to the small increase in internal battery temperature, significantly reducing the vehicle's energy utilization.

[0003] As a lithium-ion power battery, its internal resistance increases at low temperatures. At this time, the power battery consumes electrical energy during the charging or discharging process, and this energy is converted into heat. Based on this characteristic of lithium-ion batteries, there is currently a method of heating the power battery by controlling the pure electric vehicle motor controller to generate alternating positive and negative AC current on the DC side of the power battery. The generated AC current reacts with the internal resistance of the power battery to achieve thermal heating (rapid heating of the power battery through the heat generated by repeated charging and discharging of the power battery). However, this traditional high-frequency rapid heating solution treats the power battery pack as a whole for high-frequency charging and discharging heating. The charging and discharging of the power battery can only be performed alternately. Moreover, since no current is generated in the zero-vector state of the motor, the effective value of the current generated on the DC bus is low.

[0004] Therefore, it is necessary to design a power battery heating system to solve the problem of low effective value of current generated on the DC bus of the power battery and low heating efficiency in the existing high-speed heating solution of the power battery. Summary of the Invention

[0005] Embodiments of the present invention provide a power battery heating system, heating control method, device and equipment to solve the problem in the prior art that, in a high-speed heating solution for a power battery, the effective value of the current generated on the DC bus of the power battery is low and the heating efficiency is low.

[0006] In order to solve the above technical problems, the embodiments of the present invention provide the following technical solutions:

[0007] An embodiment of the present invention provides a power battery heating system, comprising:

[0008] A battery pack, and a motor controller connected to the battery pack;

[0009] The battery pack includes: a first battery module and a second battery module connected in parallel; the positive electrode of the first battery module is connected to the positive electrode of the second battery module through a first switch;

[0010] The positive electrode of the first battery module is connected to the upper bridge arm of the first target phase in the insulated gate bipolar transistor IGBT module of the motor controller through a second switch;

[0011] The positive electrode of the second battery module is connected to the upper bridge arm of the second target phase and the upper bridge arm of the third target phase in the IGBT module respectively through a third switch;

[0012] The negative electrode of the first battery module and the negative electrode of the second battery module are respectively connected to the lower bridge arm of the first target phase, the lower bridge arm of the second target phase, and the lower bridge arm of the third target phase in the IGBT module through a fourth switch;

[0013] The upper bridge arm of the first target phase is connected to the upper bridge arm of the second target phase through a fifth switch.

[0014] Optionally, the battery pack further includes: a first voltage detection module and a second voltage detection module;

[0015] The first voltage detection module is connected in parallel with the first battery module, and the first voltage detection module is used to obtain the output voltage of the first battery module;

[0016] The second voltage detection module is connected in parallel with the second battery module, and the second voltage detection module is used to obtain the output voltage of the second battery module.

[0017] Optionally, the battery pack further includes: a first resistor and a sixth switch;

[0018] Wherein, the first resistor and the sixth switch are connected in series;

[0019] The first resistor and the sixth switch are connected in series and connected in parallel with the third switch.

[0020] Optionally, the battery pack further includes: a third voltage detection module;

[0021] One end of the third voltage detection module is connected to the first connection point, and the other end of the third voltage detection module is connected to the second connection point;

[0022] The first connection point is located between the first resistor and the sixth switch; the second connection point is located between the fourth switch and the first negative terminal;

[0023] The fourth switch is connected to the first target phase lower bridge arm, the second target phase lower bridge arm, and the third target phase lower bridge arm in the IGBT module respectively through the first negative port.

[0024] Optionally, the battery pack further includes: a fourth voltage detection module;

[0025] One end of the fourth voltage detection module is connected to the third connection point, and the other end of the fourth voltage detection module is connected to the fourth connection point;

[0026] The third connection point is located between the second switch and the first positive terminal; the fourth connection point is located between the fourth switch and the first negative terminal;

[0027] Wherein, the second switch is connected to the upper bridge arm of the first target phase in the IGBT module through the first positive port;

[0028] The fourth switch is connected to the first target phase lower bridge arm, the second target phase lower bridge arm, and the third target phase lower bridge arm in the IGBT module respectively through the first negative port.

[0029] Optionally, the battery pack further includes: a fifth voltage detection module;

[0030] One end of the fifth voltage detection module is connected to the fifth connection point, and the other end of the fifth voltage detection module is connected to the sixth connection point;

[0031] The fifth connection point is located between the third switch and the second positive terminal; the sixth connection point is located between the fourth switch and the first negative terminal;

[0032] The third switch is connected to the upper bridge arm of the second target phase and the upper bridge arm of the third target phase in the IGBT module through the second positive port respectively;

[0033] The fourth switch is connected to the first target phase lower bridge arm, the second target phase lower bridge arm, and the third target phase lower bridge arm in the IGBT module respectively through the first negative port.

[0034] Optionally, the motor controller further comprises: a first capacitor and a second capacitor;

[0035] Wherein, the first capacitor is connected in parallel with the upper bridge arm and the lower bridge arm of the first target phase;

[0036] The second capacitor is connected in parallel with the upper bridge arm and the lower bridge arm of the second target phase, or the upper bridge arm and the lower bridge arm of the third target phase.

[0037] Optionally, the motor controller further comprises: a second resistor;

[0038] The second resistor is connected in parallel with the IGBT module.

[0039] Optionally, the motor controller further includes: a sixth voltage detection module;

[0040] The sixth voltage detection module is connected in parallel with the IGBT module.

[0041] Optionally, when the first switch is closed, the second switch is open, the third switch is closed, the fourth switch is closed, and the fifth switch is closed, the first battery module and the second battery module are used to provide high voltage power to the motor controller.

[0042] Optionally, when the second battery module fails, the first switch is disconnected, the second switch is closed, the third switch is disconnected, the fourth switch is closed, and the fifth switch is closed, the first battery module is used to provide high voltage power to the motor controller.

[0043] Optionally, when the first battery module fails, the first switch is disconnected, the second switch is disconnected, the third switch is closed, the fourth switch is closed, and the fifth switch is closed, the second battery module is used to provide high voltage power to the motor controller.

[0044] An embodiment of the present invention further provides a heating control method, comprising:

[0045] When the first switch is open, the second switch is closed, the third switch is closed, the fourth switch is closed, and the fifth switch is open, a control signal for controlling the on / off of a bridge arm in the IGBT module of the motor controller is obtained according to the D-axis current command and the Q-axis current command of the drive motor;

[0046] The control signal is used to control the first battery module in the battery pack to discharge and the second battery module to charge, and / or to control the second battery module in the battery pack to discharge and the first battery module to charge.

[0047] Optionally, the control signal includes:

[0048] A first control signal for instructing the upper bridge arm of the first target phase in the IGBT module to be turned on or off;

[0049] A second control signal for instructing the upper bridge arm of the second target phase in the IGBT module to be turned on or off;

[0050] a third control signal for instructing the upper bridge arm of the third target phase in the IGBT module to be turned on or off;

[0051] A fourth control signal for instructing the lower bridge arm of the first target phase in the IGBT module to be turned on or off;

[0052] a fifth control signal for instructing the lower bridge arm of the second target phase in the IGBT module to be turned on or off;

[0053] A sixth control signal for instructing the lower bridge arm of the third target phase in the IGBT module to be turned on or off.

[0054] Optionally, when the first control signal indicates that the upper bridge arm of the first target phase is turned on, the second control signal indicates that the upper bridge arm of the second target phase is turned off, the third control signal indicates that the upper bridge arm of the third target phase is turned off, the fourth control signal indicates that the lower bridge arm of the first target phase is turned off, the fifth control signal indicates that the lower bridge arm of the second target phase is turned on, and the sixth control signal indicates that the lower bridge arm of the third target phase is turned on, the control signal is used to control the output first current of the first battery module to pass through the upper bridge arm of the first target phase, enter the drive motor, and be divided into a first sub-current and a second sub-current, and to make the first sub-current pass through the lower bridge arm of the second target phase and the second sub-current pass through the lower bridge arm of the third target phase to return to the first battery module.

[0055] Optionally, when the first control signal indicates that the upper bridge arm of the first target phase is turned on, the second control signal indicates that the upper bridge arm of the second target phase is turned on, the third control signal indicates that the upper bridge arm of the third target phase is turned on, the fourth control signal indicates that the lower bridge arm of the first target phase is disconnected, the fifth control signal indicates that the lower bridge arm of the second target phase is disconnected, and the sixth control signal indicates that the lower bridge arm of the third target phase is disconnected, the control signal is used to control the first sub-current stored in the drive motor to pass through the upper bridge arm of the second target phase and the second sub-current stored in the drive motor to pass through the upper bridge arm of the third target phase to merge into a second current and return to the second battery module.

[0056] Optionally, when the first control signal indicates that the upper bridge arm of the first target phase is disconnected, the second control signal indicates that the upper bridge arm of the second target phase is turned on, the third control signal indicates that the upper bridge arm of the third target phase is turned on, the fourth control signal indicates that the lower bridge arm of the first target phase is turned on, the fifth control signal indicates that the lower bridge arm of the second target phase is disconnected, and the sixth control signal indicates that the lower bridge arm of the third target phase is disconnected, the control signal is used to control the output third current of the second battery module to pass through the upper bridge arm of the second target phase and the lower bridge arm of the third target phase, be split into a third sub-current and a fourth sub-current, and enter the drive motor, and make the third sub-current and the fourth sub-current return to the second battery module via the lower bridge arm of the first target phase.

[0057] Optionally, when the first control signal indicates that the upper bridge arm of the first target phase is turned on, the second control signal indicates that the upper bridge arm of the second target phase is turned on, the third control signal indicates that the upper bridge arm of the third target phase is turned on, the fourth control signal indicates that the lower bridge arm of the first target phase is disconnected, the fifth control signal indicates that the lower bridge arm of the second target phase is disconnected, and the sixth control signal indicates that the lower bridge arm of the third target phase is disconnected, the control signal is used to control the third sub-current and the fourth sub-current stored in the drive motor to be merged into a fourth current, and returned to the first battery module via the upper bridge arm of the first target phase.

[0058] Optionally, before obtaining a control signal for controlling the on / off switching of a bridge arm in an IGBT module of a motor controller according to a D-axis current command and a Q-axis current command of the drive motor, the method further includes:

[0059] Determine the D-axis initial current command and the Q-axis initial current command of the drive motor;

[0060] Obtaining a Q-axis current fluctuation coefficient according to the acquired Q-axis actual current value and the D-axis initial current command;

[0061] Obtaining a D-axis current command according to the Q-axis current fluctuation coefficient and the D-axis initial current command;

[0062] A Q-axis current command is obtained according to the Q-axis initial current command.

[0063] Optionally, obtaining a Q-axis current fluctuation coefficient according to the acquired Q-axis actual current value and the D-axis initial current command includes:

[0064] Obtaining an initial Q-axis current fluctuation coefficient according to the Q-axis actual current value and the D-axis initial current command;

[0065] The initial Q-axis current fluctuation coefficient is limited according to a preset maximum value of the fluctuation coefficient and a preset minimum value of the fluctuation coefficient to obtain the Q-axis current fluctuation coefficient.

[0066] An embodiment of the present invention further provides a heating control device, comprising:

[0067] a first processing module, configured to obtain a control signal for controlling the on / off of a bridge arm in an IGBT module of a motor controller according to a D-axis current command and a Q-axis current command of the drive motor when the first switch is open, the second switch is closed, the third switch is closed, the fourth switch is closed, and the fifth switch is open;

[0068] The control signal is used to control the first battery module in the battery pack to discharge and the second battery module to charge, and / or to control the second battery module in the battery pack to discharge and the first battery module to charge.

[0069] Optionally, the control signal includes:

[0070] A first control signal for instructing the upper bridge arm of the first target phase in the IGBT module to be turned on or off;

[0071] A second control signal for instructing the upper bridge arm of the second target phase in the IGBT module to be turned on or off;

[0072] A third control signal for instructing the upper bridge arm of the third target phase in the IGBT module to be turned on or off;

[0073] A fourth control signal for instructing the lower bridge arm of the first target phase in the IGBT module to be turned on or off;

[0074] a fifth control signal for instructing the lower bridge arm of the second target phase in the IGBT module to be turned on or off;

[0075] A sixth control signal for instructing the lower bridge arm of the third target phase in the IGBT module to be turned on or off.

[0076] Optionally, when the first control signal indicates that the upper bridge arm of the first target phase is turned on, the second control signal indicates that the upper bridge arm of the second target phase is turned off, the third control signal indicates that the upper bridge arm of the third target phase is turned off, the fourth control signal indicates that the lower bridge arm of the first target phase is turned off, the fifth control signal indicates that the lower bridge arm of the second target phase is turned on, and the sixth control signal indicates that the lower bridge arm of the third target phase is turned on, the control signal is used to control the output first current of the first battery module to pass through the upper bridge arm of the first target phase, enter the drive motor, and be divided into a first sub-current and a second sub-current, and to make the first sub-current pass through the lower bridge arm of the second target phase and the second sub-current pass through the lower bridge arm of the third target phase to return to the first battery module.

[0077] Optionally, when the first control signal indicates that the upper bridge arm of the first target phase is turned on, the second control signal indicates that the upper bridge arm of the second target phase is turned on, the third control signal indicates that the upper bridge arm of the third target phase is turned on, the fourth control signal indicates that the lower bridge arm of the first target phase is disconnected, the fifth control signal indicates that the lower bridge arm of the second target phase is disconnected, and the sixth control signal indicates that the lower bridge arm of the third target phase is disconnected, the control signal is used to control the first sub-current stored in the drive motor to pass through the upper bridge arm of the second target phase and the second sub-current stored in the drive motor to pass through the upper bridge arm of the third target phase to merge into a second current and return to the second battery module.

[0078] Optionally, when the first control signal indicates that the upper bridge arm of the first target phase is disconnected, the second control signal indicates that the upper bridge arm of the second target phase is turned on, the third control signal indicates that the upper bridge arm of the third target phase is turned on, the fourth control signal indicates that the lower bridge arm of the first target phase is turned on, the fifth control signal indicates that the lower bridge arm of the second target phase is disconnected, and the sixth control signal indicates that the lower bridge arm of the third target phase is disconnected, the control signal is used to control the output third current of the second battery module to pass through the upper bridge arm of the second target phase and the lower bridge arm of the third target phase, be split into a third sub-current and a fourth sub-current, and enter the drive motor, and make the third sub-current and the fourth sub-current return to the second battery module via the lower bridge arm of the first target phase.

[0079] Optionally, when the first control signal indicates that the upper bridge arm of the first target phase is turned on, the second control signal indicates that the upper bridge arm of the second target phase is turned on, the third control signal indicates that the upper bridge arm of the third target phase is turned on, the fourth control signal indicates that the lower bridge arm of the first target phase is disconnected, the fifth control signal indicates that the lower bridge arm of the second target phase is disconnected, and the sixth control signal indicates that the lower bridge arm of the third target phase is disconnected, the control signal is used to control the third sub-current and the fourth sub-current stored in the drive motor to be merged into a fourth current, and returned to the first battery module via the upper bridge arm of the first target phase.

[0080] Optionally, the device further comprises:

[0081] A first determining module is used to determine a D-axis initial current command and a Q-axis initial current command of the drive motor;

[0082] A second processing module is used to obtain a Q-axis current fluctuation coefficient according to the obtained Q-axis actual current value and the D-axis initial current command;

[0083] a third processing module, configured to obtain a D-axis current command according to the Q-axis current fluctuation coefficient and the D-axis initial current command;

[0084] The fourth processing module is used to obtain a Q-axis current command according to the Q-axis initial current command.

[0085] Optionally, the second processing module includes:

[0086] a first processing unit, configured to obtain an initial Q-axis current fluctuation coefficient according to the Q-axis actual current value and the D-axis initial current command;

[0087] The second processing unit is configured to limit the initial Q-axis current fluctuation coefficient according to a preset maximum value of the fluctuation coefficient and a preset minimum value of the fluctuation coefficient to obtain the Q-axis current fluctuation coefficient.

[0088] An embodiment of the present invention further provides a heating control device, comprising: a processor, a memory, and a program stored in the memory and executable on the processor, wherein the program, when executed by the processor, implements the steps of the heating control method as described above.

[0089] An embodiment of the present invention further provides a readable storage medium having a program stored thereon. When the program is executed by a processor, the steps in any one of the above heating control methods are implemented.

[0090] The beneficial effects of the present invention are:

[0091] The present invention provides a power battery heating system, which can not only provide a high-voltage power supply to a motor controller through a battery pack in a normal working mode, that is, when the first switch is closed, the second switch is disconnected, the third switch is closed, the fourth switch is closed, and the fifth switch is closed, but also control the first battery module in the battery pack to discharge and the second battery module to charge, and / or control the second battery module in the battery pack to discharge and the first battery module to charge, when the first switch is disconnected, the second switch is closed, the third switch is closed, the fourth switch is closed, and the fifth switch is disconnected, that is, the first battery module performs a complete charging and discharging process, and / or the second battery module performs a complete charging and discharging process, and uses the heat generated by the thermal reaction between the current and the internal resistance of the battery during the charging and discharging process to heat the power battery, thereby improving the heating rate. This can solve the problem of low effective value of the current generated on the DC bus of the power battery and low heating efficiency in the existing high-speed heating scheme of the power battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0092] Figure 1 A circuit diagram showing a power battery heating system provided by an embodiment of the present invention;

[0093] Figure 2 One of the simplified schematic diagrams of the power battery heating system provided by an embodiment of the present invention is shown;

[0094] Figure 3 A second simplified schematic diagram showing a power battery heating system according to an embodiment of the present invention;

[0095] Figure 4 A third simplified schematic diagram showing a power battery heating system according to an embodiment of the present invention;

[0096] Figure 5 A flowchart showing a heating control method provided by an embodiment of the present invention;

[0097] Figure 6 A flowchart illustrating a power battery rapid heating control function implementation according to an embodiment of the present invention is shown;

[0098] Figure 7 A fourth simplified schematic diagram showing a power battery heating system according to an embodiment of the present invention;

[0099] Figure 8 A fifth simplified schematic diagram showing a power battery heating system provided by an embodiment of the present invention;

[0100] Figure 9 A sixth simplified schematic diagram showing a power battery heating system according to an embodiment of the present invention;

[0101] Figure 10A seventh simplified schematic diagram showing a power battery heating system according to an embodiment of the present invention;

[0102] Figure 11 An eighth simplified schematic diagram showing a power battery heating system according to an embodiment of the present invention;

[0103] Figure 12 A current regulation flow chart provided by an embodiment of the present invention is shown;

[0104] Figure 13 A schematic structural diagram of a heating control device provided in an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0105] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0106] The present invention addresses the problem in the prior art that, in a high-frequency heating scheme for a power battery, the effective value of the current generated on the DC bus of the power battery is low and the heating efficiency is low. The present invention provides a power battery heating system, a heating control method, a device and an apparatus.

[0107] like Figure 1 As shown, an embodiment of the present invention provides a power battery heating system, comprising:

[0108] A battery pack, and a motor controller connected to the battery pack;

[0109] The battery pack includes: a first battery module B1 and a second battery module B2 connected in parallel; the positive electrode of the first battery module B1 is connected to the positive electrode of the second battery module B2 through a first switch S1;

[0110] The positive electrode of the first battery module B1 is connected to the upper bridge arm of the first target phase in the insulated gate bipolar transistor IGBT module of the motor controller through the second switch S2;

[0111] The positive electrode of the second battery module B2 is connected to the upper bridge arm of the second target phase and the upper bridge arm of the third target phase in the IGBT module respectively through the third switch S3;

[0112] The negative electrode of the first battery module B1 and the negative electrode of the second battery module B2 are respectively connected to the lower bridge arm of the first target phase, the lower bridge arm of the second target phase, and the lower bridge arm of the third target phase in the IGBT module through the fourth switch S4;

[0113] The upper bridge arm of the first target phase is connected to the upper bridge arm of the second target phase through a fifth switch S5.

[0114] In an embodiment of the present invention, the battery pack and the motor controller are connected through three ports, which include two positive ports and one negative port, each of which includes a sub-port on the battery pack and a sub-port on the motor controller, wherein one of the positive ports is Figure 1 The other positive terminal is Figure 1 The "②+" shown in the figure is the negative terminal. Figure 1 “③-” shown in .

[0115] The motor controller is also connected to the drive motor.

[0116] The battery pack of the embodiment of the present invention is a high-voltage battery pack, which includes two battery modules B1 and B2. The design standards of these two battery modules are completely consistent, that is, the output voltage and battery capacity of the two battery modules are exactly the same. Please continue to read Figure 1 The battery pack also includes an insulation detection circuit I1 connected in parallel with the first battery module B1, and an insulation detection circuit I2 connected in parallel with the second battery module B2. The insulation detection circuit is used to check the insulation performance of the power battery. The insulation detection circuit is an existing technical solution and will not be described in detail here.

[0117] The first battery module B1 is also connected to the fuse F1, and the second battery module B2 is also connected to the fuse F2. In the event of unexpected high current or thermal runaway, the fuse will blow, achieving passive disconnection of the power battery heating system to ensure the safety of the entire vehicle.

[0118] The fourth switch S4 is the negative pole relay switch of the battery pack, and the first switch S1 is a parallel relay of the first battery module B1 and the second battery module B2 inside the battery pack. In the normal control mode, the relay S1 is closed. At this time, the first battery module B1 and the second battery module B2 are in a parallel state and jointly output voltage to ensure the power supply of the entire vehicle. In the power battery heating mode, the relay S1 is in a disconnected state. At this time, the first battery module B1 and the second battery module B2 respectively output voltage to the outside to ensure the power supply of the entire vehicle. However, in the power battery heating mode, the relay is in a disconnected state, and the fifth switch S5 is controlled to be disconnected by the motor controller. At this time, the first battery module B1 and the second battery module B2 respectively output voltage to the outside to ensure the realization of the function of the motor controller to control the rapid heating of the power battery.

[0119] Specifically, the second switch S2 and the third switch S3 are the positive relays of the battery pack. In the normal control mode, the first switch S1 relay is closed to ensure that the first battery module B1 and the second battery module B2 are in parallel. At the same time, the relay S3 is closed and the relay S2 is disconnected. At this time, the battery pack outputs positive power through the port "①+" to supply power to the entire vehicle. In the power battery heating mode, the relay S1 is disconnected, and the relay S2 and the relay S3 are both in the closed state. At this time, the battery pack outputs positive power through the port "①+" and the port "②+" respectively, thereby ensuring the realization of the battery rapid heating function of the motor controller.

[0120] Inside the motor controller, the fifth switch S5 is a power battery speed heating control relay. In normal working mode, the relay S5 is in a closed state. At this time, the first target phase (U phase), the second target phase (V phase) and the third target phase (W phase) in the insulated gate bipolar transistor (IGBT) module are in parallel. In the power battery heating mode, the relay S5 is disconnected.

[0121] Optionally, the battery pack further includes: a first voltage detection module V1 and a second voltage detection module V2;

[0122] The first voltage detection module V1 is connected in parallel with the first battery module B1, and the first voltage detection module V1 is used to obtain the output voltage of the first battery module B1;

[0123] The second voltage detection module V2 is connected in parallel with the second battery module B2, and the second voltage detection module V2 is used to obtain the output voltage of the second battery module B2.

[0124] Please refer to Figure 1 The first voltage detection module V1 is connected in parallel with the first battery module B1. The first voltage detection module V1 is used to obtain the output voltage of the first battery module B1. That is, the first voltage detection module V1 is the voltage detection circuit of the first battery module B1 and is used to obtain the output voltage of the first battery module B1. The voltage value of this output voltage will be used to implement the relevant control logic of the battery management system. The second voltage detection module V2 is connected in parallel with the second battery module B2. The second voltage detection module V2 is used to obtain the output voltage of the second battery module B2. That is, the second voltage detection module V2 is the voltage detection circuit of the second battery module B2 and is used to obtain the output voltage of the second battery module B2. The voltage value of this output voltage will be used to implement the relevant control logic of the battery management system.

[0125] Optionally, the battery pack further includes: a first resistor R1 and a sixth switch S6;

[0126] Wherein, the first resistor R1 and the sixth switch S6 are connected in series;

[0127] The first resistor R1 and the sixth switch S6 connected in series are connected in parallel with the third switch S3.

[0128] In the embodiment of the present invention, please continue to refer to Figure 1 The first resistor R1 is a pre-charging resistor, and the sixth switch S6 is a pre-charging relay. The pre-charging resistor R1 and the pre-charging relay S6 are connected in series to form a high-voltage pre-charging circuit. During the normal high-voltage process of the vehicle, relays S2, S3 and S6 are in the disconnected state, and relay S1 is in the closed state. First, the negative pole relay S4 of the battery pack needs to be closed, and then the pre-charging relay S6 is closed. Under the action of the pre-charging resistor R1, the positive pole of the battery pack outputs the positive pole voltage through the port "①+", and the output positive pole voltage will gradually increase to the output voltage of the battery module. When the pre-charging is completed (the output positive pole voltage is basically the same as the output voltage of the first battery module B1 and the second battery module B2), the relay S3 is closed, and then the pre-charging relay S6 is disconnected. The above pre-charging process can avoid the impact of the output voltage of the power battery on the high-voltage DC bus connection components during the power-on process.

[0129] Optionally, the battery pack further includes: a third voltage detection module V3;

[0130] One end of the third voltage detection module V3 is connected to the first connection point, and the other end of the third voltage detection module V3 is connected to the second connection point;

[0131] The first connection point is located between the first resistor R1 and the sixth switch S6; the second connection point is located between the fourth switch S4 and the first cathode port;

[0132] The fourth switch S4 is connected to the first target phase lower bridge arm, the second target phase lower bridge arm, and the third target phase lower bridge arm in the IGBT module respectively through the first negative port.

[0133] Please refer to Figure 1 One end of the third voltage detection module V3 is connected between the first resistor R1 and the sixth switch S6, and the other end of the third voltage detection module V3 is connected between the fourth switch S4 and the first negative port. The third voltage detection module V3 is a pre-charge voltage detection circuit, which is used to detect the voltage state of the DC bus during the pre-charging process, so as to realize pre-charging control.

[0134] The first negative terminal is Figure 1 The negative terminal "③-" is shown.

[0135] Optionally, the battery pack further includes: a fourth voltage detection module V4;

[0136] One end of the fourth voltage detection module V4 is connected to the third connection point, and the other end of the fourth voltage detection module V4 is connected to the fourth connection point;

[0137] The third connection point is located between the second switch S2 and the first positive terminal; the fourth connection point is located between the fourth switch S4 and the first negative terminal;

[0138] The second switch S2 is connected to the upper bridge arm of the first target phase in the IGBT module through the first positive port;

[0139] The fourth switch S4 is connected to the first target phase lower bridge arm, the second target phase lower bridge arm, and the third target phase lower bridge arm in the IGBT module respectively through the first cathode port.

[0140] Please refer to Figure 1 One end of the fourth voltage detection module V4 is connected between the second switch S2 and the first positive port, and the other end of the fourth voltage detection module V4 is connected between the fourth switch S4 and the first negative port. The fourth voltage detection module V4 is an output voltage detection circuit of the battery pack, which is used to detect the output voltage of the battery pack "②+" in the power battery heating mode. The voltage value of the output voltage is used to implement the control logic of the battery management system.

[0141] The first positive terminal is Figure 1 The positive terminal "②+" is shown in the figure, and the first negative terminal is Figure 1 The negative terminal "③-" is shown in the figure.

[0142] Optionally, the battery pack further includes: a fifth voltage detection module V5;

[0143] One end of the fifth voltage detection module V5 is connected to the fifth connection point, and the other end of the fifth voltage detection module V5 is connected to the sixth connection point;

[0144] The fifth connection point is located between the third switch S3 and the second positive terminal; the sixth connection point is located between the fourth switch S4 and the first negative terminal;

[0145] The third switch S3 is connected to the upper bridge arm of the second target phase and the upper bridge arm of the third target phase in the IGBT module through the second positive port respectively;

[0146] The fourth switch S4 is connected to the first target phase lower bridge arm, the second target phase lower bridge arm, and the third target phase lower bridge arm in the IGBT module respectively through the first cathode port.

[0147] Please refer to Figure 1 One end of the fifth voltage detection module V5 is connected between the third switch S3 and the second positive electrode port, and the other end of the fifth voltage detection module V5 is connected between the fourth switch S4 and the first negative electrode port. The fifth voltage detection module V5 is an output voltage detection circuit of the battery pack, which is used to detect the output voltage of the battery pack "①+" under the normal working mode of the power battery. The voltage value of the output voltage is used to implement the control logic of the battery management system.

[0148] The second positive terminal is Figure 1 The positive electrode port "①+" shown in the figure, the first negative electrode port is Figure 1 The negative terminal "③-" is shown in the figure.

[0149] Optionally, the motor controller further includes: a first capacitor C1 and a second capacitor C2;

[0150] Wherein, the first capacitor C1 is connected in parallel with the upper bridge arm and the lower bridge arm of the first target phase;

[0151] The second capacitor C1 is connected in parallel with the upper bridge arm and the lower bridge arm of the second target phase, or the upper bridge arm and the lower bridge arm of the third target phase.

[0152] Please refer to Figure 1 The first capacitor C1 and the second capacitor C2 are the bus capacitors of the motor controller. In the normal working mode, since the relay S5 is closed, the first capacitor C1 and the second capacitor C2 are in parallel and are used to stabilize the DC bus voltage. In the power battery heating mode, the relay S5 is disconnected, and the first capacitor C1 is the first target phase (U phase) bridge arm in the IGBT module to stabilize the bus supply voltage. The first capacitor C1 is the second target phase (V phase) and the third target phase (W phase) bridge arm in the IGBT module to stabilize the bus supply voltage.

[0153] Optionally, the motor controller further includes: a second resistor R2;

[0154] The second resistor R2 is connected in parallel with the IGBT module.

[0155] Please refer to Figure 1 The second resistor R2 is connected in parallel with the IGBT module. The second resistor R2 is an active discharge resistor of the motor controller, which is used to realize system discharge during the power-off process of the entire vehicle.

[0156] Optionally, the motor controller further includes: a sixth voltage detection module V6;

[0157] The sixth voltage detection module V6 is connected in parallel with the IGBT module.

[0158] Please refer to Figure 1 The sixth voltage detection module V6 is connected in parallel with the IGBT module. The sixth voltage detection module V6 is a DC bus voltage detection circuit of the motor controller under normal working mode, which is used to measure the DC bus voltage to realize its own control logic.

[0159] The above describes the circuit structure of the power battery heating system. Next, the specific functions of the power battery heating system are described.

[0160] Optionally, when the first switch S1 is closed, the second switch S2 is open, the third switch S3 is closed, the fourth switch S4 is closed, and the fifth switch S5 is closed, the first battery module B1 and the second battery module B2 are used to provide high voltage power to the motor controller.

[0161] It should be noted that the power battery heating system provided in the embodiment of the present invention has a redundant power supply function, please refer to Figure 2 , Figure 2 This is a simplified schematic diagram of the power battery heating system. Figure 2 For the general Figure 1 The unnecessary circuit structure is removed. Figure 2 In the state shown, that is, when the power battery heating system is in normal operating mode and the power battery modules are fault-free (both the first battery module B1 and the second battery module B2 are fault-free), relay S1 in the battery pack is closed, relay S2 is disconnected, relay S3 is closed, and relays S4 and S5 are also closed. In this state, the first battery module B1 and the second battery module B2 are in a normal parallel state. After parallel connection, high-voltage DC power is provided to the motor controller through the battery pack's positive terminal "①+" and negative terminal "③-".

[0162] Optionally, when the second battery module B2 fails, the first switch S1 is disconnected, the second switch S2 is closed, the third switch S3 is disconnected, the fourth switch S4 is closed, and the fifth switch S5 is closed, the first battery module B1 is used to provide high voltage power to the motor controller.

[0163] Please note that Figure 3 , Figure 3 This is a simplified schematic diagram of the power battery heating system. Figure 3 For the general Figure 1 The unnecessary circuit structure is removed. Figure 3In the state shown, the power battery heating system is operating normally, but the first battery module B1 has a fault. Relay S1 in the battery pack is disconnected, relay S2 is closed, relay S3 is disconnected, and relays S4 and S5 are also closed. In this state, the first battery module B1 is disconnected and isolated due to the fault, and the second battery module B2 assumes the system power supply function, providing high-voltage DC power to the motor controller through the battery pack's positive terminal "②+" and negative terminal "③-."

[0164] Optionally, when the first battery module B1 fails, the first switch S1 is disconnected, the second switch S2 is disconnected, the third switch S3 is closed, the fourth switch S4 is closed, and the fifth switch S5 is closed, the second battery module B2 is used to provide high voltage power to the motor controller.

[0165] Please note that Figure 4 , Figure 4 This is a simplified schematic diagram of the power battery heating system. Figure 4 For the general Figure 1 The unnecessary circuit structure is removed. Figure 4 In the state shown, the power battery heating system is operating normally, but the second battery module B2 has a fault. Relay S1 and S2 are disconnected, while relay S3 is closed. Relays S4 and S5 are also closed. In this state, the second battery module B2 is disconnected and isolated due to the fault, and the first battery module B1 assumes the system power supply function, providing high-voltage DC power to the motor controller through the battery pack's positive terminal "①+" and negative terminal "③-."

[0166] It should also be noted that the power battery heating system provided in the embodiment of the present invention has a redundant power supply function. The power battery heating system fully utilizes the characteristics of the dual-module high-voltage power battery. Through reasonable switch design, the characteristics of the dual-module high-voltage power battery can be fully utilized. When one of the modules fails, the faulty module is isolated and the fault-free battery module is used to continue to power the drive system, thereby achieving power supply redundancy and ensuring the basic power requirements of the entire vehicle, so as not to cause the vehicle to "break down", thereby greatly improving the driving experience of the entire vehicle in a faulty state.

[0167] like Figure 5 As shown, an embodiment of the present invention provides a heating control method, including:

[0168] Step 501: When the first switch is open, the second switch is closed, the third switch is closed, the fourth switch is closed, and the fifth switch is open, a control signal for controlling the on / off of a bridge arm in an IGBT module of a motor controller is obtained according to a D-axis current command and a Q-axis current command of a driving motor;

[0169] The control signal is used to control the first battery module in the battery pack to discharge and the second battery module to charge, and / or to control the second battery module in the battery pack to discharge and the first battery module to charge.

[0170] It should be noted that the power battery heating system provided by the embodiments of the present invention has a rapid power battery heating function. Specifically, based on the D-axis and Q-axis current commands of the drive motor, control signals for the six bridge arms of the three target phases in the IGBT module are generated, controlling the discharge of the first battery module and the charging of the second battery module, and / or the discharge of the second battery module and the charging of the first battery module. During the charging and discharging process, the generated current and the internal resistance of the battery module generate heat, which is used to rapidly heat the power battery.

[0171] Optionally, the control signal includes:

[0172] A first control signal for instructing the upper bridge arm of the first target phase in the IGBT module to be turned on or off;

[0173] A second control signal for instructing the upper bridge arm of the second target phase in the IGBT module to be turned on or off;

[0174] A third control signal for instructing the upper bridge arm of the third target phase in the IGBT module to be turned on or off;

[0175] A fourth control signal for instructing the lower bridge arm of the first target phase in the IGBT module to be turned on or off;

[0176] a fifth control signal for instructing the lower bridge arm of the second target phase in the IGBT module to be turned on or off;

[0177] A sixth control signal for instructing the lower bridge arm of the third target phase in the IGBT module to be turned on or off.

[0178] The principle of the power battery rapid heating function provided by the embodiment of the present invention is described below:

[0179] By giving the D and Q axis current commands in the vector control of the permanent magnet synchronous motor (drive motor), the current loop is adjusted to make the D and Q axis currents actually generated during the motor's power battery rapid heating process consistent with the given current commands.

[0180] Specifically, see Figure 6 , Figure 6 The flow chart for realizing the power battery rapid heating control function provided in the embodiment of the present invention first determines the D-axis and Q-axis current commands Id and Iq required for the vector control of the permanent magnet synchronous motor. The current commands are used together with the D-axis and Q-axis current values Id* and Iq* actually fed back by the permanent magnet synchronous motor (obtained after coordinate transformation by collecting the three-phase currents of the motor, namely, the U-phase, V-phase and W-phase currents) for the current loop control in the vector control. The D-axis and Q-axis voltage commands Ud and Uq in the rotating coordinate system of the permanent magnet synchronous motor are obtained through current loop regulation control. The voltage commands will be used for space vector pulse width modulation (SVPWM) in the vector control of the permanent magnet synchronous motor to obtain the control signals of the upper and lower bridge arms of the U-phase, V-phase and W-phase of the IGBT module. The obtained control signals are then used to control the power conversion module (IGBT module) to drive the permanent magnet synchronous motor to work, thereby forming a closed-loop control, that is, the actual D-axis and Q-axis currents Id* and Iq* of the motor are consistent with the current commands Id and Iq. The heating control method described in the embodiment of the present invention is also through Figure 6 The “D-axis and Q-axis current command determination” link shown in , that is, the control signals of the upper and lower bridge arms of the U-phase, V-phase and W-phase of the IGBT module are generated through the current commands of the D-axis and Q-axis in the permanent magnet synchronous motor vector control, thereby realizing rapid heating of the power battery. Although the charging and discharging of the two battery modules inside the power battery can be realized by directly controlling the on and off of the upper and lower bridge arms of the U-phase, V-phase and W-phase of the IGBT module, thereby realizing rapid heating of the power battery, the control method of directly controlling the on and off of the six bridge arms of the IGBT module belongs to open-loop control. In actual application, the voltage deviation between the two modules inside the power battery, the motor rotor position detection error and other factors will generate a current component in the Q-axis of the motor. This current component will drive the motor to generate unexpected torque output, and this torque will cause the vehicle to vibrate or even move, which is undesirable. In an embodiment of the present invention, through Figure 6 The closed-loop control method shown in the figure generates control signals for the upper and lower bridge arms of the IGBT module U-phase, V-phase, and W-phase by giving current commands to the D-axis and Q-axis, thereby achieving rapid heating of the power battery, reducing the generation of unexpected torque output, and thus reducing vehicle vibration.

[0181] In an embodiment of the present invention, the control signals of the upper and lower bridge arms of the U phase are the first control signal and the fourth control signal respectively; the control signals of the upper and lower bridge arms of the V phase are the second control signal and the fifth control signal respectively; and the control signals of the upper and lower bridge arms of the W phase are the third control signal and the sixth control signal respectively.

[0182] The following specifically describes how the charging and discharging process of the battery module inside the power battery is achieved through control signals of the upper and lower bridge arms of the three-phase U phase, V phase, and W phase.

[0183] See also Figure 7 , Figure 7 This is a simplified schematic diagram of the power battery heating system in power battery heating mode. Figure 1 The circuit diagram of the power battery heating system shown can be equivalent to Figure 7 As shown, the first switch S1 is controlled to be open, the second switch S2 is controlled to be closed, the third switch S3 is controlled to be closed, the fourth switch S4 is controlled to be closed, and the fifth switch S5 is controlled to be open.

[0184] First, define the control signals of the upper and lower bridge arms of the U-phase, V-phase, and W-phase of the IGBT module. The control signal of the U-phase upper bridge arm (first control signal), the control signal of the U-phase lower bridge arm (second control signal), the control signal of the V-phase upper bridge arm (third control signal), the control signal of the V-phase lower bridge arm (fourth control signal), the control signal of the W-phase upper bridge arm (fifth control signal), and the control signal of the W-phase lower bridge arm (sixth control signal) are represented by T1, T2, T3, T4, T5, and T6 respectively. When the control signal is "1", it indicates that the corresponding bridge arm is turned on. When the control signal is "0", it indicates that the corresponding bridge arm is turned off.

[0185] Optionally, when the first control signal indicates that the upper bridge arm of the first target phase is turned on, the second control signal indicates that the upper bridge arm of the second target phase is turned off, the third control signal indicates that the upper bridge arm of the third target phase is turned off, the fourth control signal indicates that the lower bridge arm of the first target phase is turned off, the fifth control signal indicates that the lower bridge arm of the second target phase is turned on, and the sixth control signal indicates that the lower bridge arm of the third target phase is turned on, the control signal is used to control the output first current of the first battery module to pass through the upper bridge arm of the first target phase, enter the drive motor, and be divided into a first sub-current and a second sub-current, and to make the first sub-current pass through the lower bridge arm of the second target phase and the second sub-current pass through the lower bridge arm of the third target phase to return to the first battery module.

[0186] Specifically, see Figure 8 , when the control signals of T1-T6 are (1 0 0 0 1 1) in sequence, Figure 7 The equivalent circuit diagram shown is Figure 8 At this time, the second battery module B2 in the battery pack is in a disconnected state, and the first battery module B1 in the battery pack outputs current. The first battery module B1 outputs current i aThe first current (i.e., the first current) passes through the upper bridge arm of the IGBT module's U phase and enters the motor's three-phase winding, where it is split into current i1 (the first sub-current) and current i2 (the second sub-current). It then returns to the negative electrode of the first battery module B1 via the lower bridge arms of the IGBT module's V and W phases. This process is actually the discharge process of the first battery module B1.

[0187] Further, when the first control signal indicates that the upper bridge arm of the first target phase is turned on, the second control signal indicates that the upper bridge arm of the second target phase is turned on, the third control signal indicates that the upper bridge arm of the third target phase is turned on, the fourth control signal indicates that the lower bridge arm of the first target phase is disconnected, the fifth control signal indicates that the lower bridge arm of the second target phase is disconnected, and the sixth control signal indicates that the lower bridge arm of the third target phase is disconnected, the control signal is used to control the first sub-current stored in the drive motor to pass through the upper bridge arm of the second target phase and the second sub-current stored in the drive motor to pass through the upper bridge arm of the third target phase to merge into a second current and return to the second battery module.

[0188] Specifically, after a certain period of time (establishing the current i) when the control signals of T1 to T6 are (1 0 0 0 1 1) in sequence, a , current i1, current i2), control the drive motor to enter the zero vector state, correspondingly, the control signals of T1 to T6 are (1 1 10 0 0) in sequence. When the control signals of T1-T6 are (1 1 1 0 0 0) in sequence, Figure 7 The equivalent circuit diagram shown is Figure 9 shown.

[0189] Figure 9 In the equivalent circuit shown, the motor system is in an active short-circuit state. At this time, the first battery module B1 is Figure 8 The conduction path established in the circuit is disconnected, but under the action of the inductance energy storage of the three-phase winding of the motor, there will still be current i1 and current i2. The current i1 passes through the upper bridge arm of the V phase of the IGBT module, and the current i2 passes through the upper bridge arm of the W phase of the IGBT module and is combined into i b (second current) and returns to the second battery module B2 in the battery pack. In this process, the second battery module B2 is actually charged.

[0190] Figure 8 and Figure 9 The equivalent circuit shown actually realizes the energy conversion process of discharging the first battery module B1 and charging the second battery module B2 through the inductive energy storage function of the three-phase winding of the motor.

[0191] Optionally, when the first control signal indicates that the upper bridge arm of the first target phase is disconnected, the second control signal indicates that the upper bridge arm of the second target phase is turned on, the third control signal indicates that the upper bridge arm of the third target phase is turned on, the fourth control signal indicates that the lower bridge arm of the first target phase is turned on, the fifth control signal indicates that the lower bridge arm of the second target phase is disconnected, and the sixth control signal indicates that the lower bridge arm of the third target phase is disconnected, the control signal is used to control the output third current of the second battery module to pass through the upper bridge arm of the second target phase and the lower bridge arm of the third target phase, be split into a third sub-current and a fourth sub-current, and enter the drive motor, and make the third sub-current and the fourth sub-current return to the second battery module via the lower bridge arm of the first target phase.

[0192] Specifically, see Figure 8 , when the control signals of T1-T6 are (0 1 1 1 0 0) in sequence, Figure 7 The equivalent circuit diagram shown is Figure 10 At this time, the first battery module B1 inside the battery pack is in an isolated state, and the second battery module B2 in the battery pack outputs current. The second battery module B2 outputs current i c The third current is shunted through the V-phase and W-phase upper bridge arms of the IGBT module (divided into currents i3 and i4) before entering the motor winding. It then flows through the U-phase lower bridge arm of the IGBT module and is fed back to the negative electrode of the second battery module B2. This process is actually the discharge process of the second battery module B2.

[0193] Further, when the first control signal indicates that the upper bridge arm of the first target phase is turned on, the second control signal indicates that the upper bridge arm of the second target phase is turned on, the third control signal indicates that the upper bridge arm of the third target phase is turned on, the fourth control signal indicates that the lower bridge arm of the first target phase is disconnected, the fifth control signal indicates that the lower bridge arm of the second target phase is disconnected, and the sixth control signal indicates that the lower bridge arm of the third target phase is disconnected, the control signal is used to control the third sub-current and the fourth sub-current stored in the drive motor to be merged into a fourth current, and returned to the first battery module via the upper bridge arm of the first target phase.

[0194] Specifically, after a certain period of time (establishing the current i) the control signals of T1 to T6 are (0 1 1 1 0 0) in sequence, c , current i3, current i4), control the drive motor to enter the zero vector state, correspondingly, the control signals of T1 to T6 are (1 1 10 0 0) in sequence. When the control signals of T1-T6 are (1 1 1 0 0 0) in sequence, Figure 7 The equivalent circuit diagram shown is Figure 11 shown.

[0195] Figure 11 In the equivalent circuit shown, the motor system is in an active short-circuit state. At this time, the second battery module B2 is Figure 10 The conduction path established in the circuit is disconnected, but under the action of the inductance energy storage of the three-phase winding of the motor, there will still be current i3 and current i4. The current i3 passes through the upper bridge arm of the V phase of the IGBT module, and the current i4 passes through the upper bridge arm of the W phase of the IGBT module, which are combined into i d (fourth current) and returns to the first battery module B1 in the battery pack. In this process, the first battery module B1 is actually charged.

[0196] Preferably, the heating control method described in the embodiment of the present invention sequentially controls the six bridge arms of the IGBT module to achieve four complete charge and discharge cycles: discharging the first battery module, charging the second battery module, discharging the second battery module, and charging the first battery module. Each battery module undergoes a charge and discharge cycle. The current generated during the charge and discharge process and the internal resistance of the battery generate heat, which is used to rapidly heat the power battery.

[0197] Optionally, before obtaining a control signal for controlling the on / off switching of a bridge arm in an IGBT module of a motor controller according to a D-axis current command and a Q-axis current command of the drive motor, the method further includes:

[0198] Determine the D-axis initial current command and the Q-axis initial current command of the drive motor;

[0199] Obtaining a Q-axis current fluctuation coefficient according to the acquired Q-axis actual current value and the D-axis initial current command;

[0200] Obtaining a D-axis current command according to the Q-axis current fluctuation coefficient and the D-axis initial current command;

[0201] A Q-axis current command is obtained according to the Q-axis initial current command.

[0202] Regarding the Q-axis current of the motor causing the motor's unexpected torque output, it can be seen as follows: The torque formula of the permanent magnet synchronous motor is:

[0203]

[0204] Among them, T e Indicates the motor output torque, p0 indicates the number of motor pole pairs, i d with i q Respectively represent the actual D and Q axis currents of the motor; L d With L q represents the equivalent inductance of the motor D and Q axes; ψ rRepresents the permanent magnet flux. According to the torque formula, when the motor Q-axis current is 0, no matter what the D-axis current is, the motor output torque T e If the Q axis current is not 0, the motor will generate output torque. In the embodiment of the present invention, the motor's D axis current command is set to a sine wave, and the Q axis current command is set to 0. Figure 6 The "permanent magnet synchronous motor vector control current loop adjustment" makes the actual D-axis and Q-axis currents of the motor consistent with the command current, thereby realizing the power battery heating process and reducing the unexpected torque output of the drive motor caused by the Q-axis current.

[0205] However, due to the influence of factors such as the motor rotor position analysis error, a current component will inevitably be generated on the Q-axis of the motor during the rapid heating control of the power battery. The greater the current fluctuation, the more severe the unexpected output torque fluctuation of the motor caused by this. Therefore, in order to further weaken the unexpected torque generated by the drive motor during the heating control process, the embodiment of the present invention creatively proposes the concept of Q-axis current fluctuation coefficient to characterize the fluctuation degree of the Q-axis current, and then compensates the D-axis current command according to the Q-axis current fluctuation coefficient, thereby weakening the unexpected torque generated by the drive motor during the rapid heating control process.

[0206] That is, see Figure 12 The current regulation process provided by the embodiment of the present invention includes step 1201: determining the initial current commands of the D-axis and Q-axis; step 1202: calculating the Q-axis current fluctuation coefficient; and step 1203: compensating the D-axis current command. In step 1201, the D-axis current command Id and the Q-axis current command Iq required for the rapid heating control of the power battery are first determined; then, in step 1202, the compensation coefficient is calculated based on the actual Q-axis current of the permanent magnet synchronous motor. In step 1203, the D-axis current command is compensated based on the Q-axis current fluctuation coefficient obtained in step 1202. That is, the D-axis current command is obtained based on the Q-axis current fluctuation coefficient and the D-axis initial current command, and the Q-axis current command is obtained based on the Q-axis initial current command, so as to weaken the unexpected torque generated by the drive motor during the rapid heating control process.

[0207] Optionally, obtaining a Q-axis current fluctuation coefficient according to the acquired Q-axis actual current value and the D-axis initial current command includes:

[0208] Obtaining an initial Q-axis current fluctuation coefficient according to the Q-axis actual current value and the D-axis initial current command;

[0209] The initial Q-axis current fluctuation coefficient is limited according to a preset maximum value of the fluctuation coefficient and a preset minimum value of the fluctuation coefficient to obtain the Q-axis current fluctuation coefficient.

[0210] Furthermore, in the "Q-axis current fluctuation coefficient calculation" link, the initial value of the Q-axis current fluctuation coefficient (initial Q-axis current fluctuation coefficient) is calculated based on the current actual value of the Q-axis current (Q-axis actual current value) and the D-axis initial current command, and the initial value of the Q-axis current fluctuation coefficient is limited according to the preset maximum value of the fluctuation coefficient and the preset minimum value of the fluctuation coefficient to obtain the final Q-axis current fluctuation coefficient, and the D-axis current command is subsequently compensated according to the final Q-axis current fluctuation coefficient.

[0211] Specifically, the specific process of current regulation provided by the embodiment of the present invention is as follows:

[0212] Determine the current command of D-axis and Q-axis:

[0213] The D-axis and Q-axis current commands of the permanent magnet synchronous motor for power battery rapid heating control provided in the embodiment of the present invention are as follows:

[0214] I d-int =K·sin(2πf)

[0215] I q-int =0

[0216] The above formula specifies the motor D-axis and Q-axis current commands for rapid heating control, where I d-int It represents the initial value of the D-axis current command (D-axis initial current command). The current adopts a sinusoidal function waveform as the control output. K represents the amplitude of the sinusoidal waveform, which is a positive real number. f represents the frequency of the sinusoidal waveform. K can be determined according to the state of the system during the rapid heating control process, such as the heating speed, the effective current value of rapid heating, etc. The frequency f of the sinusoidal waveform is recommended to be in the range of 100Hz to 250Hz. If the f value is too large, the subsequent control requirements for the rapid heating of the power battery will be higher, such as the subsequent current loop adjustment. If the frequency of the sinusoidal wave signal is too high, the quality of the current loop adjustment will deteriorate, thereby affecting the rapid heating control effect. If f is too high, it will cause high-frequency noise problems in the drive motor during the rapid heating control process. In addition, the frequency f cannot be too low. If f is too low, the Q-axis current component of the motor will increase during the control process, thereby increasing the unexpected output torque of the drive motor.

[0217] Calculation of Q-axis current fluctuation coefficient:

[0218] The concept of the Q-axis current fluctuation coefficient provided in the embodiment of the present invention is used to characterize the degree of fluctuation of the actual Q-axis current of the motor. When the Q-axis current fluctuation is severe, the fluctuation coefficient increases, and vice versa. The coefficient is calculated in real time during the power battery rapid heating control process, and the obtained fluctuation coefficient is used for subsequent D-axis current command compensation. The calculation method of the Q-axis current fluctuation coefficient is as follows:

[0219]

[0220] Calculate the initial value K of the Q-axis current fluctuation coefficient according to the above formula Q-int Where, I q* Indicates the actual current value of the current axis Q of the driving motor, f indicates the frequency of the initial current command sine wave of the D axis, max[I q* (i)] represents the maximum sampling value of the motor Q-axis current within the control cycle of the i-th D-axis sinusoidal current command, min[I q* (i)] represents the minimum sampling value of the motor Q-axis current within the control cycle of the i-th D-axis sinusoidal current command. The embodiment of the present invention collects the maximum sampling value and the minimum sampling value of the Q-axis current within the time range of 0.2f D-axis current sinusoidal waves, and squares and sums the maximum and minimum sampling values of the Q-axis current within each sinusoidal wave cycle to obtain the square sum. Finally, the square sum of the Q-axis current within 0.2f cycles is accumulated to obtain the initial value K of the Q-axis current fluctuation coefficient. Q-int It can be seen that with the increase of Q-axis current fluctuation and the increase of Q-axis current deviation from 0, K Q-int The value will increase, and the embodiment of the present invention uses this feature to characterize the fluctuation degree of the Q-axis current.

[0221] Get K Q-int Then restrict it:

[0222]

[0223] Among them, K L Indicates the limited Q-axis current fluctuation coefficient, K max With K min Respectively represent the maximum and minimum limits of the fluctuation coefficient (K max With K min are greater than 0), it can be seen that the initial value K of the Q-axis current fluctuation coefficient is Q-int Limited to [K min ,K max ] range. After completing the limitation of the initial value of the Q-axis current fluctuation coefficient, the final calculation of the Q-axis current fluctuation coefficient is performed. The specific method is as follows:

[0224]

[0225] where K Q It represents the final Q-axis current fluctuation coefficient. According to the formula, when the Q-axis current fluctuation coefficient K after limitation is L By K min Increase to K max When the fluctuation coefficient KQ It decreases linearly from 1 to 0, that is, as the Q-axis current fluctuation degree increases, the Q-axis current fluctuation coefficient decreases. The embodiment of the present invention performs subsequent compensation processing based on this characteristic of the fluctuation coefficient.

[0226] D-axis current command compensation:

[0227] The initial value I of the D-axis current command is obtained through the above content d-int and Q-axis current fluctuation coefficient K Q , using K Q to I d-int Compensation processing is performed to obtain the final D-axis and Q-axis current commands, which will be used for actual power battery speed heating control.

[0228] I d =K Q ·K·sin(2πf)

[0229] I q =0

[0230] According to the above formula, as the Q-axis fluctuation becomes more severe, the D-axis current command during the power battery rapid heating control will decrease. This reduction in the D-axis current command will reduce the battery module's charge and discharge current during the rapid heating control process, thereby reducing the current component generated in the motor's Q-axis during the control process, ultimately suppressing the motor's unexpected torque output. This power battery rapid heating control method significantly solves the problem of unexpected drive motor power output during traditional high-frequency rapid heating of power batteries, ensuring the safety and reliability of the entire vehicle system during the rapid heating process.

[0231] The high-voltage circuit of the power battery heating system provided by an embodiment of the present invention is based on a dual-module power battery design. It uses internal switches in the power battery pack to implement two operating modes for the motor controller, achieving a normal control mode and a power battery heating mode. In the power battery heating mode, the energy storage characteristics of the stator winding coils of the pure electric vehicle motor are used to achieve energy transfer between the two modules of the power battery, specifically charging one module while discharging the other. Compared to traditional power battery heating circuits based on drive motors, this high-voltage circuit can also generate current even in the zero-vector state of the motor, thereby increasing the effective value of the power battery bus current during heating control and greatly improving heating efficiency. In addition to the above, in the high-voltage circuit of the power battery heating system provided by the present invention, the internal switch design of the motor controller also realizes a redundant power supply function for the dual-module power battery. That is, if one of the power battery modules fails, the faulty module can be physically isolated, and then the non-faulty module is used to provide high-voltage power to the drive system, ensuring the basic power output of the drive system, thereby improving the driving experience of the vehicle in the fault state.

[0232] Furthermore, based on this power battery heating system, an embodiment of the present invention also provides a heating control method. This method determines the D-axis and Q-axis currents in the rotating coordinate system of the drive motor, utilizes the current loop in the vector control of the permanent magnet synchronous motor to adjust them in real time, and controls the charge and discharge currents generated within the two independent modules of the power battery, thereby achieving the power battery rapid heating function. Considering factors such as motor rotor position detection errors, the actual current component will inevitably be generated in the motor Q-axis during the actual rapid heating control process, causing the drive motor to produce unexpected torque output, thereby causing vibration and even longitudinal movement of the vehicle. This problem has not been solved in traditional high-frequency rapid heating control. To address this problem, an embodiment of the present invention designs a method for calculating the fluctuation coefficient of the Q-axis current of the permanent magnet synchronous motor. This coefficient evaluates the unexpected output torque of the drive motor during the high-speed heating control process through the actual state of the Q-axis current. When the degree of fluctuation is severe, the embodiment of the present invention reduces the charging and discharging current of the power battery module during the high-speed heating process by compensating and reducing the amplitude of the D-axis control signal of the drive motor. This dynamic adjustment reduces the current component generated in the Q-axis and reduces the unexpected output torque of the drive motor. On this basis, combined with the current loop adjustment of the permanent magnet synchronous motor, the Q-axis current of the motor is adjusted to tend to 0, thereby greatly solving the problem of unexpected power output of the drive motor during high-frequency high-speed heating of traditional power batteries, and ensuring the safety and reliability of the entire vehicle system during the high-speed heating process.

[0233] It should also be noted that the power battery heating system and heating control method provided in the embodiments of the present invention have the characteristics of clear ideas, concise and clear working principles, and easy engineering implementation of hardware circuits and control methods. At the same time, they largely solve the problem of unexpected power output of the driving motor during high-speed heating of traditional power batteries, and therefore have good engineering promotion value.

[0234] like Figure 13 As shown, an embodiment of the present invention further provides a heating control device, comprising:

[0235] A first processing module 1301 is configured to obtain a control signal for controlling the on / off of a bridge arm in an IGBT module of a motor controller according to a D-axis current command and a Q-axis current command of the drive motor when the first switch is open, the second switch is closed, the third switch is closed, the fourth switch is closed, and the fifth switch is open;

[0236] The control signal is used to control the first battery module in the battery pack to discharge and the second battery module to charge, and / or to control the second battery module in the battery pack to discharge and the first battery module to charge.

[0237] In this embodiment of the present invention, control signals for the six bridge arms of the three target phases in the IGBT module are derived based on the D-axis and Q-axis current commands of the drive motor. This control process enables the discharge of the first battery module and the charging of the second battery module, and / or the discharge of the second battery module and the charging of the first battery module. During the charging and discharging process, the generated current and the internal resistance of the battery module generate heat, which is used to rapidly heat the power battery.

[0238] Optionally, the control signal includes:

[0239] A first control signal for instructing the upper bridge arm of the first target phase in the IGBT module to be turned on or off;

[0240] A second control signal for instructing the upper bridge arm of the second target phase in the IGBT module to be turned on or off;

[0241] a third control signal for instructing the upper bridge arm of the third target phase in the IGBT module to be turned on or off;

[0242] A fourth control signal for instructing the lower bridge arm of the first target phase in the IGBT module to be turned on or off;

[0243] a fifth control signal for instructing the lower bridge arm of the second target phase in the IGBT module to be turned on or off;

[0244] A sixth control signal for instructing the lower bridge arm of the third target phase in the IGBT module to be turned on or off.

[0245] Optionally, when the first control signal indicates that the upper bridge arm of the first target phase is turned on, the second control signal indicates that the upper bridge arm of the second target phase is turned off, the third control signal indicates that the upper bridge arm of the third target phase is turned off, the fourth control signal indicates that the lower bridge arm of the first target phase is turned off, the fifth control signal indicates that the lower bridge arm of the second target phase is turned on, and the sixth control signal indicates that the lower bridge arm of the third target phase is turned on, the control signal is used to control the output first current of the first battery module to pass through the upper bridge arm of the first target phase, enter the drive motor, and be divided into a first sub-current and a second sub-current, and to make the first sub-current pass through the lower bridge arm of the second target phase and the second sub-current pass through the lower bridge arm of the third target phase to return to the first battery module.

[0246] Optionally, when the first control signal indicates that the upper bridge arm of the first target phase is turned on, the second control signal indicates that the upper bridge arm of the second target phase is turned on, the third control signal indicates that the upper bridge arm of the third target phase is turned on, the fourth control signal indicates that the lower bridge arm of the first target phase is disconnected, the fifth control signal indicates that the lower bridge arm of the second target phase is disconnected, and the sixth control signal indicates that the lower bridge arm of the third target phase is disconnected, the control signal is used to control the first sub-current stored in the drive motor to pass through the upper bridge arm of the second target phase and the second sub-current stored in the drive motor to pass through the upper bridge arm of the third target phase to merge into a second current and return to the second battery module.

[0247] Optionally, when the first control signal indicates that the upper bridge arm of the first target phase is disconnected, the second control signal indicates that the upper bridge arm of the second target phase is turned on, the third control signal indicates that the upper bridge arm of the third target phase is turned on, the fourth control signal indicates that the lower bridge arm of the first target phase is turned on, the fifth control signal indicates that the lower bridge arm of the second target phase is disconnected, and the sixth control signal indicates that the lower bridge arm of the third target phase is disconnected, the control signal is used to control the output third current of the second battery module to pass through the upper bridge arm of the second target phase and the lower bridge arm of the third target phase, be split into a third sub-current and a fourth sub-current, and enter the drive motor, and make the third sub-current and the fourth sub-current return to the second battery module via the lower bridge arm of the first target phase.

[0248] Optionally, when the first control signal indicates that the upper bridge arm of the first target phase is turned on, the second control signal indicates that the upper bridge arm of the second target phase is turned on, the third control signal indicates that the upper bridge arm of the third target phase is turned on, the fourth control signal indicates that the lower bridge arm of the first target phase is disconnected, the fifth control signal indicates that the lower bridge arm of the second target phase is disconnected, and the sixth control signal indicates that the lower bridge arm of the third target phase is disconnected, the control signal is used to control the third sub-current and the fourth sub-current stored in the drive motor to be merged into a fourth current, and returned to the first battery module via the upper bridge arm of the first target phase.

[0249] Optionally, the device further comprises:

[0250] A first determining module is used to determine a D-axis initial current command and a Q-axis initial current command of the driving motor;

[0251] A second processing module is used to obtain a Q-axis current fluctuation coefficient according to the obtained Q-axis actual current value and the D-axis initial current command;

[0252] a third processing module, configured to obtain a D-axis current command according to the Q-axis current fluctuation coefficient and the D-axis initial current command;

[0253] The fourth processing module is used to obtain a Q-axis current command according to the Q-axis initial current command.

[0254] Optionally, the second processing module includes:

[0255] a first processing unit, configured to obtain an initial Q-axis current fluctuation coefficient according to the Q-axis actual current value and the D-axis initial current command;

[0256] The second processing unit is configured to limit the initial Q-axis current fluctuation coefficient according to a preset maximum value of the fluctuation coefficient and a preset minimum value of the fluctuation coefficient to obtain the Q-axis current fluctuation coefficient.

[0257] It should be noted that the heating control device provided in the embodiment of the present invention is a device capable of executing the above-mentioned heating control method. All embodiments of the above-mentioned heating control method are applicable to the device and can achieve the same or similar technical effects.

[0258] An embodiment of the present invention further provides a heating control device, comprising a processor and a memory; the memory is used to store programs and data used by the processor when performing operations, and the processor calls and executes the programs and data stored in the memory.

[0259] The motor controller further includes a transceiver, which is used to receive and send data under the control of the processor.

[0260] Specifically, the processor is configured to obtain a control signal for controlling the on / off of a bridge arm in an IGBT module of a motor controller according to a D-axis current command and a Q-axis current command of the drive motor when the first switch is open, the second switch is closed, the third switch is closed, the fourth switch is closed, and the fifth switch is open;

[0261] The control signal is used to control the first battery module in the battery pack to discharge and the second battery module to charge, and / or to control the second battery module in the battery pack to discharge and the first battery module to charge.

[0262] Optionally, the control signal includes:

[0263] A first control signal for instructing the upper bridge arm of the first target phase in the IGBT module to be turned on or off;

[0264] A second control signal for instructing the upper bridge arm of the second target phase in the IGBT module to be turned on or off;

[0265] A third control signal for instructing the upper bridge arm of the third target phase in the IGBT module to be turned on or off;

[0266] A fourth control signal for instructing the lower bridge arm of the first target phase in the IGBT module to be turned on or off;

[0267] a fifth control signal for instructing the lower bridge arm of the second target phase in the IGBT module to be turned on or off;

[0268] A sixth control signal for instructing the lower bridge arm of the third target phase in the IGBT module to be turned on or off.

[0269] Optionally, when the first control signal indicates that the upper bridge arm of the first target phase is turned on, the second control signal indicates that the upper bridge arm of the second target phase is turned off, the third control signal indicates that the upper bridge arm of the third target phase is turned off, the fourth control signal indicates that the lower bridge arm of the first target phase is turned off, the fifth control signal indicates that the lower bridge arm of the second target phase is turned on, and the sixth control signal indicates that the lower bridge arm of the third target phase is turned on, the control signal is used to control the output first current of the first battery module to pass through the upper bridge arm of the first target phase, enter the drive motor, and be divided into a first sub-current and a second sub-current, and to make the first sub-current pass through the lower bridge arm of the second target phase and the second sub-current pass through the lower bridge arm of the third target phase to return to the first battery module.

[0270] Optionally, when the first control signal indicates that the upper bridge arm of the first target phase is turned on, the second control signal indicates that the upper bridge arm of the second target phase is turned on, the third control signal indicates that the upper bridge arm of the third target phase is turned on, the fourth control signal indicates that the lower bridge arm of the first target phase is disconnected, the fifth control signal indicates that the lower bridge arm of the second target phase is disconnected, and the sixth control signal indicates that the lower bridge arm of the third target phase is disconnected, the control signal is used to control the first sub-current stored in the drive motor to pass through the upper bridge arm of the second target phase and the second sub-current stored in the drive motor to pass through the upper bridge arm of the third target phase to merge into a second current and return to the second battery module.

[0271] Optionally, when the first control signal indicates that the upper bridge arm of the first target phase is disconnected, the second control signal indicates that the upper bridge arm of the second target phase is turned on, the third control signal indicates that the upper bridge arm of the third target phase is turned on, the fourth control signal indicates that the lower bridge arm of the first target phase is turned on, the fifth control signal indicates that the lower bridge arm of the second target phase is disconnected, and the sixth control signal indicates that the lower bridge arm of the third target phase is disconnected, the control signal is used to control the output third current of the second battery module to pass through the upper bridge arm of the second target phase and the lower bridge arm of the third target phase, be split into a third sub-current and a fourth sub-current, and enter the drive motor, and make the third sub-current and the fourth sub-current return to the second battery module via the lower bridge arm of the first target phase.

[0272] Optionally, when the first control signal indicates that the upper bridge arm of the first target phase is turned on, the second control signal indicates that the upper bridge arm of the second target phase is turned on, the third control signal indicates that the upper bridge arm of the third target phase is turned on, the fourth control signal indicates that the lower bridge arm of the first target phase is disconnected, the fifth control signal indicates that the lower bridge arm of the second target phase is disconnected, and the sixth control signal indicates that the lower bridge arm of the third target phase is disconnected, the control signal is used to control the third sub-current and the fourth sub-current stored in the drive motor to be merged into a fourth current, and returned to the first battery module via the upper bridge arm of the first target phase.

[0273] Optionally, before the processor obtains a control signal for controlling the on / off of a bridge arm in an IGBT module of the motor controller according to the D-axis current command and the Q-axis current command of the drive motor, the processor is further configured to:

[0274] Determine the D-axis initial current command and the Q-axis initial current command of the drive motor;

[0275] Obtaining a Q-axis current fluctuation coefficient according to the acquired Q-axis actual current value and the D-axis initial current command;

[0276] Obtaining a D-axis current command according to the Q-axis current fluctuation coefficient and the D-axis initial current command;

[0277] A Q-axis current command is obtained according to the Q-axis initial current command.

[0278] Optionally, the processor is specifically configured to:

[0279] Obtaining an initial Q-axis current fluctuation coefficient according to the Q-axis actual current value and the D-axis initial current command;

[0280] The initial Q-axis current fluctuation coefficient is limited according to a preset maximum value of the fluctuation coefficient and a preset minimum value of the fluctuation coefficient to obtain the Q-axis current fluctuation coefficient.

[0281] An embodiment of the present invention further provides a readable storage medium having a program stored thereon. When the program is executed by a processor, the steps in any one of the above heating control methods are implemented.

[0282] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary personnel in this technical field, several improvements and modifications can be made without departing from the principles described in the present invention. These improvements and modifications are also within the scope of protection of the present invention.

Claims

1. A power battery heating system, characterized in that: include: A battery pack, and a motor controller connected to the battery pack; The battery pack includes: a first battery module and a second battery module connected in parallel; the positive electrode of the first battery module is connected to the positive electrode of the second battery module through a first switch; The positive electrode of the first battery module is connected to the upper bridge arm of the first target phase in the insulated gate bipolar transistor IGBT module of the motor controller through a second switch; The positive electrode of the second battery module is connected to the upper bridge arm of the second target phase and the upper bridge arm of the third target phase in the IGBT module respectively through a third switch; The negative electrode of the first battery module and the negative electrode of the second battery module are respectively connected to the lower bridge arm of the first target phase, the lower bridge arm of the second target phase, and the lower bridge arm of the third target phase in the IGBT module through a fourth switch; The upper bridge arm of the first target phase is connected to the upper bridge arm of the second target phase through a fifth switch; Wherein, the motor controller further includes: a sixth voltage detection module; The sixth voltage detection module is connected in parallel with the IGBT module; When the first switch is closed, the second switch is open, the third switch is closed, the fourth switch is closed, and the fifth switch is closed, the first battery module and the second battery module are used to provide high-voltage power to the motor controller; Wherein, when the second battery module fails, the first switch is disconnected, the second switch is closed, the third switch is disconnected, the fourth switch is closed, and the fifth switch is closed, the first battery module is used to provide high-voltage power to the motor controller; Among them, when the first battery module fails, the first switch is disconnected, the second switch is disconnected, the third switch is closed, the fourth switch is closed, and the fifth switch is closed, the second battery module is used to provide high-voltage power to the motor controller.

2. The power battery heating system according to claim 1, characterized in that: The battery pack further includes: a first voltage detection module and a second voltage detection module; The first voltage detection module is connected in parallel with the first battery module, and the first voltage detection module is used to obtain the output voltage of the first battery module; The second voltage detection module is connected in parallel with the second battery module, and the second voltage detection module is used to obtain the output voltage of the second battery module.

3. The power battery heating system according to claim 1, characterized in that: The battery pack further includes: a first resistor and a sixth switch; Wherein, the first resistor and the sixth switch are connected in series; The first resistor and the sixth switch are connected in series and connected in parallel with the third switch.

4. The power battery heating system according to claim 3, characterized in that: The battery pack further includes: a third voltage detection module; One end of the third voltage detection module is connected to the first connection point, and the other end of the third voltage detection module is connected to the second connection point; The first connection point is located between the first resistor and the sixth switch; the second connection point is located between the fourth switch and the first negative terminal; The fourth switch is connected to the first target phase lower bridge arm, the second target phase lower bridge arm, and the third target phase lower bridge arm in the IGBT module respectively through the first negative port.

5. The power battery heating system according to claim 1, characterized in that: The battery pack further includes: a fourth voltage detection module; One end of the fourth voltage detection module is connected to the third connection point, and the other end of the fourth voltage detection module is connected to the fourth connection point; The third connection point is located between the second switch and the first positive terminal; the fourth connection point is located between the fourth switch and the first negative terminal; Wherein, the second switch is connected to the upper bridge arm of the first target phase in the IGBT module through the first positive port; The fourth switch is connected to the first target phase lower bridge arm, the second target phase lower bridge arm, and the third target phase lower bridge arm in the IGBT module respectively through the first negative port.

6. The power battery heating system according to claim 1, characterized in that: The battery pack further includes: a fifth voltage detection module; One end of the fifth voltage detection module is connected to the fifth connection point, and the other end of the fifth voltage detection module is connected to the sixth connection point; The fifth connection point is located between the third switch and the second positive terminal; the sixth connection point is located between the fourth switch and the first negative terminal; The third switch is connected to the upper bridge arm of the second target phase and the upper bridge arm of the third target phase in the IGBT module through the second positive port respectively; The fourth switch is connected to the first target phase lower bridge arm, the second target phase lower bridge arm, and the third target phase lower bridge arm in the IGBT module respectively through the first negative port.

7. The power battery heating system according to claim 1, characterized in that: The motor controller further includes: a first capacitor and a second capacitor; Wherein, the first capacitor is connected in parallel with the upper bridge arm and the lower bridge arm of the first target phase; The second capacitor is connected in parallel with the upper bridge arm and the lower bridge arm of the second target phase, or the upper bridge arm and the lower bridge arm of the third target phase.

8. The power battery heating system according to claim 1, characterized in that: The motor controller further includes: a second resistor; The second resistor is connected in parallel with the IGBT module.

9. A heating control method, applied to the power battery heating system according to any one of claims 1 to 8, characterized in that: The method comprises: When the first switch is open, the second switch is closed, the third switch is closed, the fourth switch is closed, and the fifth switch is open, a control signal for controlling the on / off of a bridge arm in the IGBT module of the motor controller is obtained according to the D-axis current command and the Q-axis current command of the drive motor; The control signal is used to control the first battery module in the battery pack to discharge and the second battery module to charge, and / or to control the second battery module in the battery pack to discharge and the first battery module to charge; Wherein, the control signal includes: A first control signal for instructing the upper bridge arm of the first target phase in the IGBT module to be turned on or off; A second control signal for instructing the upper bridge arm of the second target phase in the IGBT module to be turned on or off; a third control signal for instructing the upper bridge arm of the third target phase in the IGBT module to be turned on or off; A fourth control signal for instructing the lower bridge arm of the first target phase in the IGBT module to be turned on or off; a fifth control signal for instructing the lower bridge arm of the second target phase in the IGBT module to be turned on or off; a sixth control signal for instructing the lower bridge arm of the third target phase in the IGBT module to be turned on or off; Wherein, when the first control signal indicates that the upper bridge arm of the first target phase is turned on, the second control signal indicates that the upper bridge arm of the second target phase is turned off, the third control signal indicates that the upper bridge arm of the third target phase is turned off, the fourth control signal indicates that the lower bridge arm of the first target phase is turned off, the fifth control signal indicates that the lower bridge arm of the second target phase is turned on, and the sixth control signal indicates that the lower bridge arm of the third target phase is turned on, the control signal is used to control the output first current of the first battery module to pass through the upper bridge arm of the first target phase, enter the drive motor, be split into a first sub-current and a second sub-current, and make the first sub-current pass through the lower bridge arm of the second target phase and the second sub-current pass through the lower bridge arm of the third target phase to return to the first battery module; Wherein, when the first control signal indicates that the upper bridge arm of the first target phase is turned on, the second control signal indicates that the upper bridge arm of the second target phase is turned on, the third control signal indicates that the upper bridge arm of the third target phase is turned on, the fourth control signal indicates that the lower bridge arm of the first target phase is disconnected, the fifth control signal indicates that the lower bridge arm of the second target phase is disconnected, and the sixth control signal indicates that the lower bridge arm of the third target phase is disconnected, the control signal is used to control the first sub-current stored in the drive motor to pass through the upper bridge arm of the second target phase and the second sub-current stored in the drive motor to pass through the upper bridge arm of the third target phase to be combined into a second current, and return to the second battery module; Wherein, when the first control signal indicates that the upper bridge arm of the first target phase is disconnected, the second control signal indicates that the upper bridge arm of the second target phase is turned on, the third control signal indicates that the upper bridge arm of the third target phase is turned on, the fourth control signal indicates that the lower bridge arm of the first target phase is turned on, the fifth control signal indicates that the lower bridge arm of the second target phase is disconnected, and the sixth control signal indicates that the lower bridge arm of the third target phase is disconnected, the control signal is used to control the output third current of the second battery module to pass through the upper bridge arm of the second target phase and the lower bridge arm of the third target phase, be split into a third sub-current and a fourth sub-current, and enter the drive motor, and make the third sub-current and the fourth sub-current return to the second battery module via the lower bridge arm of the first target phase; Among them, when the first control signal indicates that the upper bridge arm of the first target phase is turned on, the second control signal indicates that the upper bridge arm of the second target phase is turned on, the third control signal indicates that the upper bridge arm of the third target phase is turned on, the fourth control signal indicates that the lower bridge arm of the first target phase is disconnected, the fifth control signal indicates that the lower bridge arm of the second target phase is disconnected, and the sixth control signal indicates that the lower bridge arm of the third target phase is disconnected, the control signal is used to control the third sub-current and the fourth sub-current stored in the drive motor to be merged into a fourth current, and returned to the first battery module via the upper bridge arm of the first target phase.

10. The heating control method according to claim 9, characterized in that: Before obtaining a control signal for controlling the on / off switching of a bridge arm in an IGBT module of a motor controller according to a D-axis current command and a Q-axis current command of the drive motor, the method further includes: Determine the D-axis initial current command and the Q-axis initial current command of the drive motor; Obtaining a Q-axis current fluctuation coefficient according to the acquired Q-axis actual current value and the D-axis initial current command; Obtaining a D-axis current command according to the Q-axis current fluctuation coefficient and the D-axis initial current command; A Q-axis current command is obtained according to the Q-axis initial current command.

11. The heating control method according to claim 10, characterized in that: According to the acquired Q-axis actual current value and the D-axis initial current command, the Q-axis current fluctuation coefficient is obtained, including: Obtaining an initial Q-axis current fluctuation coefficient according to the Q-axis actual current value and the D-axis initial current command; The initial Q-axis current fluctuation coefficient is limited according to a preset maximum value of the fluctuation coefficient and a preset minimum value of the fluctuation coefficient to obtain the Q-axis current fluctuation coefficient.

12. A heating control device, applied to the heating control method according to any one of claims 9 to 11, characterized in that: The device comprises: a first processing module, configured to obtain a control signal for controlling the on / off of a bridge arm in an IGBT module of a motor controller according to a D-axis current command and a Q-axis current command of the drive motor when the first switch is open, the second switch is closed, the third switch is closed, the fourth switch is closed, and the fifth switch is open; The control signal is used to control the first battery module in the battery pack to discharge and the second battery module to charge, and / or to control the second battery module in the battery pack to discharge and the first battery module to charge; Wherein, the control signal includes: A first control signal for instructing the upper bridge arm of the first target phase in the IGBT module to be turned on or off; A second control signal for instructing the upper bridge arm of the second target phase in the IGBT module to be turned on or off; a third control signal for instructing the upper bridge arm of the third target phase in the IGBT module to be turned on or off; A fourth control signal for instructing the lower bridge arm of the first target phase in the IGBT module to be turned on or off; a fifth control signal for instructing the lower bridge arm of the second target phase in the IGBT module to be turned on or off; a sixth control signal for instructing the lower bridge arm of the third target phase in the IGBT module to be turned on or off; Wherein, when the first control signal indicates that the upper bridge arm of the first target phase is turned on, the second control signal indicates that the upper bridge arm of the second target phase is turned off, the third control signal indicates that the upper bridge arm of the third target phase is turned off, the fourth control signal indicates that the lower bridge arm of the first target phase is turned off, the fifth control signal indicates that the lower bridge arm of the second target phase is turned on, and the sixth control signal indicates that the lower bridge arm of the third target phase is turned on, the control signal is used to control the output first current of the first battery module to pass through the upper bridge arm of the first target phase, enter the drive motor, be split into a first sub-current and a second sub-current, and make the first sub-current pass through the lower bridge arm of the second target phase and the second sub-current pass through the lower bridge arm of the third target phase to return to the first battery module; Wherein, when the first control signal indicates that the upper bridge arm of the first target phase is turned on, the second control signal indicates that the upper bridge arm of the second target phase is turned on, the third control signal indicates that the upper bridge arm of the third target phase is turned on, the fourth control signal indicates that the lower bridge arm of the first target phase is disconnected, the fifth control signal indicates that the lower bridge arm of the second target phase is disconnected, and the sixth control signal indicates that the lower bridge arm of the third target phase is disconnected, the control signal is used to control the first sub-current stored in the drive motor to pass through the upper bridge arm of the second target phase and the second sub-current stored in the drive motor to pass through the upper bridge arm of the third target phase to be combined into a second current, and return to the second battery module; Wherein, when the first control signal indicates that the upper bridge arm of the first target phase is disconnected, the second control signal indicates that the upper bridge arm of the second target phase is turned on, the third control signal indicates that the upper bridge arm of the third target phase is turned on, the fourth control signal indicates that the lower bridge arm of the first target phase is turned on, the fifth control signal indicates that the lower bridge arm of the second target phase is disconnected, and the sixth control signal indicates that the lower bridge arm of the third target phase is disconnected, the control signal is used to control the output third current of the second battery module to pass through the upper bridge arm of the second target phase and the lower bridge arm of the third target phase, be split into a third sub-current and a fourth sub-current, and enter the drive motor, and make the third sub-current and the fourth sub-current return to the second battery module via the lower bridge arm of the first target phase; Among them, when the first control signal indicates that the upper bridge arm of the first target phase is turned on, the second control signal indicates that the upper bridge arm of the second target phase is turned on, the third control signal indicates that the upper bridge arm of the third target phase is turned on, the fourth control signal indicates that the lower bridge arm of the first target phase is disconnected, the fifth control signal indicates that the lower bridge arm of the second target phase is disconnected, and the sixth control signal indicates that the lower bridge arm of the third target phase is disconnected, the control signal is used to control the third sub-current and the fourth sub-current stored in the drive motor to be merged into a fourth current, and returned to the first battery module via the upper bridge arm of the first target phase.

13. A heating control device, characterized in that: include: A processor, a memory, and a program stored in the memory and executable on the processor, wherein when the program is executed by the processor, the steps of the heating control method according to any one of claims 9 to 11 are implemented.

14. A readable storage medium, characterized in that The readable storage medium stores a program, and when the program is executed by a processor, the steps in the heating control method according to any one of claims 9 to 11 are implemented.

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